I prefer phone for urgent and important matters like bank transactions , for others i prefer email, i can think before replying to them , it will help both parties ,if the email is framed properly, there will be no need for further converstions. But yeah reply does take time , it would be good if we include a php script that lets us know if they had opened our mail or not.

And for physically impaired people , there must be an option for SMS , as he said it is 2011 and technology helps :)